Ultrasonic surgical instruments arc finding increasingly widespread applications in surgical procedures by virtue of the unique performance characteristics of such instruments. Depending upon specific instrument configurations and operational parameters, ultrasonic surgical instruments can provide substantially simultaneous cutting, of tissue and hemostasis by coagulation, desirably minimizing patient trauma. The cutting action is typically effected by an end-effector at the distal end of the instrument, with the end-effector transmitting ultrasonic energy to tissue brought into contact therewith. Ultrasonic instruments of this nature can be configured for open surgical use, or laparoscopic or endoscopic surgical procedures.
Ultrasonic surgical instruments have been developed that include a clamp mechanism to press tissue against the end-effector of the instrument in order to couple ultrasonic energy to the tissue of a patient. Such an arrangement (sometimes referred to as an ultrasonic transector) is disclosed in U.S. Pat. No. 5,322,055, hereby incorporated by reference.
Optimization of the ultrasonic effect created on tissue during use of the above-type of ultrasonic instrument is achieved by efficient coupling of tissue to the end-effector of the instrument. This requires that the pivotal clamp arm of the clamping mechanism of the instrument be positionable in substantial alignment with the end-effector, recognizing that normal manufacturing tolerances of the instrument components can result in minor misalignment. Because the present apparatus is desirably configured for disposable, single-patient use, it is important that components of the device be subject to relatively economical manufacture by avoiding excessively small manufacturing tolerances.
The present invention is particularly directed to an improved arrangement for mounting the pivotal clamp arm of the present clamp coagulator apparatus. The arrangement is desirably economical in configuration, and cooperates with the associated pivotal clamp arm to position and maintain the clamp arm in substantial alignment with an associated end-effector, notwithstanding normal manufacturing tolerances of the components.